Catalytic converter construction

ABSTRACT

A CATALYTIC CONVERTER FOR TREATING EXHAUST GAS STREAMS ADAPTED FOR ENGINE COMPARTMENT INSTALLATION AND ENCOMPASSING A DESIGN THAT WILL WITHSTAND STESSES DUE TO TEMPERATURE DIFFERENTIALS WITHIN THE CONVERTER BY UTILIZING A SYMMETRICAL DESIGN WITH SLIDEABLE PARTS. IN A PREFERRED ARRANGEMENT THE CONVERTER HAS A CATALYST RESERVOIR THEREIN WHICH SERVES AS STORAGE FOR FRESH CATALYST PARTICLES THAT   FLOW INTO THE CATALYST RETAINING SECTION, REPLACING PARTICLES LOST BY ATTRITION.

Aug.. 22, 1972 DE PALMA ErAL 3,685,972

CATALYTIC CONVERTER CONSTRUCTION Filed Sept. 18. 1969 UNTREATED EXHAUST0 l/GASES FIGURE l TREATED EXHAUST GASES FIGURE 3 INVENTORS TED V. DEPALMA ALBERT J BRONS MARTIN W. PERGA ya/wzra/ flu/annp, yr J ail; 4.14-

A TTOKVEYS FIGURE 2 United States Patent Ofice 3,685,972 Patented Aug.22, 1972 3,685,972 CATALYTIC CONVERTER CONSTRUCTION Ted V. De Palma,Rte. 3, Box 294, Roselle, Ill. 60172;

Albert J. Brons, 533 S. Princeton Ave., Villa Park, Ill.

60181; and Martin W. Perga, 576 Edgefield Lane, Holiman Estates, Ill.60172 Filed Sept. 18, 1969, Ser. No. 858,917 Int. Cl. F0111 3/14; Blj9/04 US. Cl. 23-288 F 7 Claims ABSTRACT OF THE DISCLOSURE The presentinvention relates to an improved catalytic converter for use in thecatalytic oxidation and conversion of exhaust gas streams and moreparticularly to a converter construction which incorporates asymmetrical construction of slideable parts, thus preventing structuraldamage due to temperature differentials within the converter.

The desirability of removing or converting the noxious compounds ofvehicular exhaust gases has been generally Well established. Theunavoidable incomplete combustion of hydrocarbon fuels by a gasolineengine results in the generation of substantial quantities of unburnedhydrocarbons, and undesirable products, which, as waste products,discharge into the atmosphere through the exhaust line. Such partiallyoxidized products, and parts or all of these components contribute tothe smog problem presently facing various geographical areas of theworld.

In a catalytic operation, the hot gases issuing from the motor exhaustmanifold are passed through a catalyst bed maintained within aconversion zone, so as to effect a more or less complete oxidation ofcarbon monoxide and unburned hydrocarbons present in the exhaust stream.It is sometimes desirable topremix the exhaust gases issuing from theexhaust manifold with a quantity of secondary or combustion air beforedirecting the gases into the converter; however, this is no longerconsidered absolutely necessary in a converter system, since moderncarburetion systems initially provide a supply of excess air to theengine, thus establishing surplus air in the exhaust stream in mostmodes of operation. The use of a catalytic method in apparatus providesfor the initiation of the oxidation reaction at a lower temperature thanmight otherwise be possible, and its use effectively eliminates the needfor an igniting means, such as a spark plug, which is generally usedwith most types of after burners or other apparatus which dependstrictly upon thermal conditions.

One of the major problems encountered in the use of a catalyticconverter in an exhaust system is the problem of structural failureinduced by large thermal gradients within the converter. Hightemperatures are produced as a result of the exothermic oxidationreaction taking place within and around the catalyst bed. Depending uponthe particular catalyst employed and the operation of the motor vehicle,that is, whether the engine is being operated under conditions of idle,accelerate, cruise, or decelerate, converter temperatures may run ashigh as 1200 degrees to 2000 degrees Fahrenheit. A practical catalystconverter construction that is susceptible to converter for treating anengine exhaust gas, which may cause deformation, split seams, etc., as aresult of uneven thermal expansion.

A practical converter should also be arranged so that a uniformdistribution of exhaust gas flow through the catalyst bed is maintainedin order to achieve maximum catalyst life and maximum conversion. It isalso important that the physical size of the converter be minimized, yetproviding maximum catalyst volume, thus permitting the installation ofthe converter in the engine compartment of the automobile or, in otherwords, in the closest possible proximity to the engine exhaust gasmanifold;

It is thus the principal object of this invention to provide for acatalytic converter construction that allows for the various componentsof the converter to expand and contract relative to each other as thetemperature of the apparatus fluctuates. Another object of thisinvention is to provide for a simplified converter constructionutilizing a symmetrical design.

Still another object of this invention is to provide for a catalystconverter construction that is susceptible to simplification ofmanufacturing techniques.

In a broad aspect, this invention provides a catalytic converter fortreating an engine exhaust gas, which comprises in combination, an outerhousing which has an elongated tubular body section and opposing sealedend sections, a first port means through said one end section and asecond port means through the opposing section, a tapered, tubular-form,perforate section having an interior closed end and an open end, saidtapered, tubularform, perforate section having its said open endconnecting to said outer housing, and the remaining portion spacedwithin said outer housing to form a manifold section therearound, acentral tubular-form perforate section having an open end and aninternal end spaced centrally within said tapered tubular-form perforatesection to thereby provide an annular-form catalyst retaining sectionfor containment of said catalyst particles, the open end of said centraltubular-form perforate section extending to and connecting with one ofsaid port means, and the internal end thereof extending to andconnecting slideably into said interior closed end of said tapered,tubular-form section.

Preferably, the interior closed end of the tapered tubular-formperforate section is supported by a series of spaced apart projectionsor other form of spacing means spaced from an end section of theconverter. Thus, that end is supported in a manner permittinglongitudinal expansion of the tapered section.

In a preferred embodiment, and particularly for a substantiallyvertically positioned converter, an enclosed reservoir section means islocated at one of the ends of the tapered tubular-form perforate sectionto form a catalyst reservoir adjacent to the catalyst retaining section.Openings or other passageway means are then provided from the reservoirsection to the catalyst retaining section. Thus, when the converter isvertically disposed, or nearly so, with the catalyst reservoir sectionmeans located above the retaining section, catalyst particles within thereservoir will flow downward through these openings into the catalystretaining section to fill any voids created by attrition or shrinkage.The vertical positioning of this particular converter embodiment isconsidered a preferred arrangement, for it not only establishes catalystparticle flow from the reservoir downward through the openings into thecatalyst retaining section, but, in the case where the inlet gases areintroduced through the uppermost port means, the vertical positioningestablishes downward exhaust gas flow through the catalyst retainingsection. This downward flow of exhaust gases is generally thought to bea preferred flow pattern, i.e., the downward flow of exhaust gasesthrough a catalytic bed generally causes catalyst particles to be packedtightly throughout the retaining section. The present converter designmay well be used in a generally horizontal position, or in a verticalposition with the inlet gases being introduced through the lowermostport means, thus resulting in upward flow, but an upward flow of exhaustgases will generally cause catalyst particles to float within thecatalyst retaining section. Floating of catalyst particles introduces amajor problem into the operation of the converter, that being the lossof catalyst particles through attrition. Since the particles are ineffect floating they are moving relative to each other. This relativemotion causes the particles to rub together, gradually wearing down thesize of each particle. As the particles diminish in size, theyeventually will be lost through the perforations in the perforate Wallsections. This loss, although relatively small in a short period oftime, can affect the operation of the converter over an extended periodof time. This is especially troublesome today, since it is thought thata properly designed converter may well last up to 50,000 miles ofoperation time.

In a preferred embodiment, the outer elongated tubular body section andthe centrally located tubular-form perforate section are cylindricallyshaped, and the tapered tubular-form perforate section isfrusto-conically shaped. In addition, all sections of the converter areco-axially disposed about the longitudinal axis of the outer tubularbody section. In other words, the axes of the end sections, as well asthe axis of the tapered tubular-form perforate section and the axistubular-form perforate section coincide with the axis of the outerelongated tubular body section. Also, when a reservoir section isembodied in the converter, that section should be co-axially disposed onthe longitudinal axis of the elongated tubular body section.

Thus, a basic feature of this preferred embodiment is that anycross-sectional area taken transverse to the longitudinal axis of theouter tubular body section is symmetrical with respect to that axis.Since the average direction of flow to the catalyst retaining section issubstantially parallel to this longitudinal axis, and as a directconsequence of the symmetrical cross section of the cylindrical andconical sections, an essentially uniform temperature pattern, ortemperature symmetry, is obtained throughout the catalyst retainingsection, and, more importantly, throughout the end sections and wallsections of the outer housing itself. In other words, an infinite numberof substantially circular concentric temperature isotherms, centered onthe longitudinal axis of the outer housing, exist in both of the endsection members and in all other members disposed perpendicularly to thelongitudinal axis, and an infinite number of peripheral, longitudinallyspaced isotherms exist in the walls of the elongated outer tubular bodysection and in the walls of the perforate sections. Thus thetemperatures at all points equidistant from the longitudinal axis will,on the average, be equal. There will, of course, usually be asubstantial temperature differential between the centers of the endsections, but the rate of change of temperature with path length inproceeding therebetween along the surface of the housing and theperforate sections is quite small, and the temperature profile of allminimum distance path lengths between the centers of the end sectionswill be substantially identical. Such temperature symmetry means thatthe thermal stress pattern within the sections will also be symmetricalso that excessive differential stresses within the structural members ofthe converter are avoided. This feature, in addition to the feature ofslidable perforate sections, will thus avoid any structural problems dueto temperature differentials within the system.

The converter may well be used in either an "in-to-out flow arrangementor an out-to-in flow arrangement. In the latter arrangement, it isdesirous that the open end of the tapered tubular-form perforate sectionbe the wider end thereof. Thus, the manifold section circumventing thatperforate section will decrease in crosssectional area in the directionof flow. Assuming that the centrally located tubular-form perforatesection is cylindrically shaped, the catalyst retaining section willincrease in cross-sectional area in the direction of flow. Both theseconditions or limitations of cross-sectional areas will establish anideal flow pattern through the retaining section.

Preferably, in the former or in-to-out fiow arrangement, the open end ofthe tapered tubular-form perforate section is the narrower end thereof.This again establishes a catalyst retaining section of increasingcross-sectional area in the direction of flow, assuming however, thatthe centrally located tubular-form section is cylindrically shaped. Toestablish an ideal sized manifold section around the taperedtubular-form perforate section. The elongated tubular body section istapered to effect an increase in cross-sectional area of the manifoldsection from a location laterally adjacent the open or narrower end ofthe tapered perforate section to a location laterally adjacent theinterior closed end. In other words the manifold, in this case servingas the outlet manifold section, will increase in cross-sectional area inthe direction of flow.

In a preferred arrangement the end sections have outwardly facingflanged portions, and the outer diameters of these end sections coincidewith the interior diameters of the tubular body section. They arethereby adapted to be disposed concurrently within the tubular bodysection with their open ends facing outwardly. This type of connectionwill permit the utilization of various production methods to permanentlyor temporarily seal the end sections to the tubular body section.

It is noted that in accordance with the requirements of symmetry setforth herein before, that the transverse section of the chamber mayassume other than cylindrical forms, as for example an oval or a polygonof n sides; however, the desired form is cylindrical because of itsabsolute symmetry and the ease of fabrication. The design andconstruction of the present improved converter, as well as otheradvantageous features in connection therewith, are better set forth andexplained by reference to the accompanying diagrammatic drawing and thefollowing description thereof.

DESCRIPTION OF THE DRAWING FIG. 1 is a sectional elevational viewthrough a preferred embodiment of this converter best suited foroutto-in flow.

FIG. 2 is a partial, sectional elevational view through an embodiment ofthis converter which embodies an alternate form of support for thetubular-form perforate section.

FIG. 3 is a simplified schematical representation of a modifiedembodiment of the present converter which is best suited for in-to-outflow.

With reference to the drawing, and particularly to FIG. 1, the converteris shown to include an outer housing 1 which has an elongated outertubular body section 2, to which are connected end closure sections 3and 4 respectively, thereby forming an enclosed chamber of circularcross section having a central longitudinal axis a-a.

In this present embodiment, which is best suited for out-to-in flow, theupper and lower end sections are provided with flanged portions 5 and16, and the outer diameters of these sections coincide with the interiordiameters of the tubular body section. Thus, there are providedperipheral surfaces 6 and 7 for abutting the interior of tubular section2 at 8 and 9 respectively. It is noted that the type of connectionresulting from the use of end sections 3 and 4 will permit theutilization of various production techniques to seal the connectioneither permanently or temporarily. For example, such an arrangement willpermit the use of welding, either by establishing edge joint welds atand 11, or the use of resistance welding to establish a joint at 12 and13. It is also contemplated that this connection be sealed by use of aclamping device either temporarily or permanently. Still further, theconnection may be sealed by turning and rolling the two mating surfacesinwardly or outwardly to produce a tin can type joint construction. 0nthe other hand, it is contemplated that end sections 3 and 4 may be flatplates, thus permitting a simple weld connection to section 2. It isalso contemplated that section 2 may be flanged to facilitate varioustypes of connections.

To maintain the symmetrical construction, a conduit or other suitableport means, which in this particular arrangement serves as the inletconduit, is located along axis a-a and communicates with the interior ofthe body section 2 via opening 17. Likewise a conduit 18 or othersuitable port means is disposed along axis a-a at the lower end of theconverter and an opening 19 is provided in the lower end section 4 toestablish communication to the interior of the body section 2. Thisparticular conduit serves as the outlet conduit in the preferredutilization of this embodiment.

A tapered tubular-form perforate section 20, in this case beingconically shaped, is attached at its open, wide end to the interior ofsection 2 of the housing at zone 21. Apertures or slotted openings 22are provided in the walls of conically shaped member 20, therebyestablishing communication into the annularly shaped catalyst bed orretaining section 23, formed by the conically shaped section and anaxially positioned central tubular-form section 24. Being conicallyshaped, section 20 establishes a resulting tapered annular manifoldsection 25. Also, since the central tubular-form perforate section 24 iscylindrically shaped, the annularly shaped catalyst retaining section 23has a resulting cross section that increases in the downward directionor in the preferred direction of flow.

It may be pointed out that radial flow through an annular form of bedcatalyst is of particular advantage in fluid-solids contacting, in thatit provides a substantially uniform flow through a relatively largesurface area. However, where a relatively high velocity gaseous streamis introduced into a converter and diverted radially through a uniformlythick annular-form catalyst bed, there tends to be a non-uniform flowalong the axis of such bed. Particularly with a high mass flow ratethrough a uniform depth of annular bed, there is a tendency for a majorportion of the gas stream to bypass the upstream end portion of the bedand to flow radially through the downstream end portion. Actually, asportions of the total gas flow pass through the bed, the velocity of theremaining gas flow within the inlet manifold is reduced to result in adecreased velocity head and an increased static head from the upstreamto the downstream end of the inlet zone. This differential static headgradient causes an increased flow through the bed, when moving from theupstream to the downstream end of the unit, and this inequality of flowbecomes progressively less as the total flow rate increases.

Thus, by utilizing a tapering annular bed or retaining section, creatinggreater particle depth in the downstream end of the unit, a greaterpressure drop through that portion will be established, and there willbe a tendency to balance the higher static head at such portion. Theresult is a decreased flow rate through the retaining section at thedownstream end and a more uniform flow through the entire annular-formcatalyst retaining section. It is therefore seen that this particularembodiment is best suited for out-to-in flow.

It is to be noted also that by incorporating the tapered annularmanifold section 25 as the inlet manifold section for the distributionof the exhaust gas stream flow within the interior of the converter,that the effect of the velocity head of the exhaust stream upon thecatalyst is further minimized. The reduction in the cross-sectional areaof the manifold of the gas flow together with the increasingcross-sectional area of the catalyst bed 23 in the downward directionprovides for a substantially uniform flow or driving force across thecatalyst bed at any one point.

In addition to being defined by perforate sections 20 and 24, thecatalyst retaining section 23 is further defined by the lower endsection 4 and by the interior closed end 30 of tapered tubular-formperforate section 20. Interior end 30 may be an imperforate platesection with a groove or pocket portion in its central position;however, in this present embodiment, the portion 31 is a hollow cylinderor pocket with its axis located concurrently on axis aa. Its innerdiameter is approximately the same diameter as the outer diameter ofperforate section 24. Thus, section 24 is supported in a slideablemanner by the indented portion 31 of imperforate plate 30. Thisparticular construction permits the perforate section 24 to expandlongitudinally within the space 32 provided by portion 31. Therefore,space 32 between the end of section 24 and the end of grooved section 31should be designed to a sufficient size to allow for the calculatedlongitudinal expansion. As mentioned previously, any lateral expansionis compensated for by its design being basically symmetrical about axisa-a.

In a simplified arrangement imperforate plate 30 would not have anyopenings therein. However, this illustrated arrangement embodies acatalyst reservoir section means 35, which in this particular instanceis formed by an additional hollow, frustro-conically shaped imperforatemember 36 attached to perforate section 20 at 37. With the use ofreservoir 35 the plate 30 is provided with openings or other suitablepassageway means 38 to in turn provide communication into the catalystretaining section 23. Of course, openings 38 must be of suflicient sizeto pass catalyst particles therethrough.

An alternate arrangement for supporting section 24 is illustrated inFIG. 2. There section 24 is shown being supported slideably by anopening 31 centrally located in interior closed end 30'. Since section24 is free to expand longitudinally, and since under normal operatingconditions its temperature will be higher than that of conically shapedsection 20, it will expand greater than section 20. This relative motionwill tend to transfer pressure to the catalyst particles withinreservoir section 35 and thus force the particles through the opening 38into the catalyst retaining section 23.

It is to be noted that the internal components of the converter of FIG.1 are only fixed permanently at 21 and at 39 at the lower end of theconverter. The upper portion of these components are not supported inany fixed manner to the outer sections. They are, however, supported ina slideable manner by transverse projections or other suitable spacingmeans 40 spaced around the circumference of the interior of section 2and spaced from the top end section 3. The projections of the presentembodiment have been shown to be formed by a stamping operation;however, this particular form of fabrication should not be consideredlimiting for other forms of spacers are considered to be within thescope of the present designs. For instance, the projections may beformed by welding separate pieces of material to the interior walls ofbody section 2. It should also be recognized that the number ofprojections used for the purpose of supporting the upper end of theinner components should not be limiting upon this invention. However,the number should not be so great as to block flow of incoming exhaustgases. Typically, three or four such projections spaced equidistantaround the inner walls of section 2 will provide adequate guide andsupport for the internal components. It is to be noted, that similar tothe support construction of section 24, this particular constructionallows for free longitudinal expansion of section 20 within theconverter body. Alternatively, of course, the spacing means may beconnected 7 to the interior components of the converter; e.g., member36, thus obtaining the slideable support through the free contact withthe interior of body section 2.

Within the space 23, defining the catalyst retaining section, arelocated subdivided catalyst particles 41, and, for most efiicientconverter operations, the catalyst retaining section should be filled tocapacity. This is the reason for locating a reservoir section means 35above the converter bed section.

With regard to the catalyst, it is not intended to limit this improvedtype of catalytic converter to any one particular type of oxidationcatalyst, inasmuch as there are various known effective and efficientcatalyst compositions. Suitable oxidation catalysts include the metalsof groups 1, 5, 6, 7, and 8 of the Periodic Table, particularlychromium, copper, nickel, and platinum. These components may be usedsingularly, or in combinations of two or more, etc., and will generallybe composited with an inorganic refractory oxide support material, suchas alumina, silicaalumina, silica-alumina-zirconia, silica-thoria,silica-boria, or the like. It is also noted that in some instances thecatalyst retaining section may be reinforced with stiffening members,bridging the space between the perforate partitions 20 and 24.

In the operation of the converter, as best shown in FIG. 1, the exhaustgases issuing from the exhaust manifold of the automobile engine arepreferably directed into conduit and through opening 17 provided in theend plate 3 of the converter to impinge upon the end part of thereservoir section 36 near the center portion thereof. The gases are thendeflected fairly uniformly around the ends of the reservoir section downinto the annular tapered manifold section 25. Passing down through themanifold section, the high gas velocity eventually develops into afairly uniform pressure head, because of the tapered cross-sectionalarea of the manifold section 25. The gases are then directed throughperforations 22 of tapered tubular-form perforate section into thecatalyst retaining section 23. Because of the increasing size of thecatalyst retaining bed in the direction of flow, the effect of highpressure head at the downstream end of the catalyst retaim'ng sectionwill be further reduced, therefore establishing uniformity and aresulting highly efficient converter. The unburned components in theexhaust gases are oxidized within the catalyst section to form generallyharmless components therein. After oxidation, the gases are passed intocentral tubular-form perforate section 24 through perforations 22' downthrough the space defined by section 24 and out through conduit 18,which is adapted to be connected to the exhaust pipe of the automobile.

FIG. 3 is a simplified schematical representation of a modifiedembodiment of the present improvement, which is best suited forin-to-out flow. It is shown without a reservoir section, which shouldnot be limiting, for it is contemplated that a reservoir section bepositioned above the catalyst bed or retaining section to maintain thelatter in a filled state. This particular embodiment has an outerhousing 1' which has an elongated tubular body section 2' and opposingsealed end sections 3' and 4. As was the case in the embodiment of FIG.1, there are provided conduits or other suitable port means 15' and 18into the housing 1'. Conduit 15' senves as the inlet conduit into thisparticular converter. A tapered, tubular-form perforate section 20 isaffixed at its open narrower end to end section 3 of the housing.Section 20' has an interior closed end 30 having a grooved or pocketportion 31 which is sized to slideably support the central tubular-formperforate section 24. The other open end of section 24' is connected toport 15'. Thus, the perforate sections 20' and 24 form a taperedannularly shaped catalyst retaining section 23 which increases incross-sectional area in the preferred direction of flow. As set forthhereinbefore, this increase in cross-sectional area will effectuate amore uniform flow through the catalyst particles 41. To further improvethe flow characteristics of this converter, the elongated tubular bodysection 2 is tapered in the region defined by numeral 50 to therebyaffect an increase in cross-sectional area, in the preferred directionof flow, of the manifold 25' formed around section 20. Since manifold 25serves as the outlet manifold in this particular embodiment, an increasein area in the direction of flow will aid in establishing uniform flowthrough the retaining section 23'. Of course, spacing means may beprovided to slideably support tapered tubular-form section 20'.

'From the foregoing description, it is seen that this particularinvention is of such a construction that damage due to temperaturedifferentials will be eliminated or minimized. The slideable orexpansible nature of the fit of the perforate sections to theirsupporting pieces, in addition to the fact that the preferred embodimentis designed to be symmetrical about axis a-a, will prevent expansionproblems from developing. The converter also manifests a constructionthat is relatively inexpensive especially in the case of mass productiontechniques. The tubular and cylindrical shapes of the components enablesthe manufacturer to use techniques of stamping, blanking, and relativelysimple metal forming operation.

It is noted, as heretofore mentioned, that the circular shape of theouter housing 1 should not be limiting upon this present improvement,for, although this circular shape has proven to be the most convenientform, other shapes are contemplated as being within the scope of thisinvention. Preferably, however, the shape should be symmetrical aboutaxis aa. The symmetrical shape is considered an aspect of thisinvention, however, it is not considered an exclusive aspect thereof.Other shapes, symmetrical or nonsymmetrical, are considered to be withinthe scope of this present invention.

It is desirable that these components be made of a lightweightrelatively thin gauge material, whether of ordinary steel or an alloy,such that the assembly is relatively lightweight and such that thetemperature effects may also be accommodated by some material fiexurewithout causing breakage of seams and joints. The material used shouldalso be of a character that is able to withstand the high temperaturesresulting from the operation of the converter.

It is also considered as within the scope of this present improveddesign and construction to provide for a covering of the outer walls ofthe converter with a suitable insulation material, such as asbestos,mineral wool, or the like, in order to maintain the maximum amount ofheat within the catalyst retaining section. It may be understood thatvarious minor modifications in the design and or location of the variousportions of this converter may be made without diverting from the scopeof the present invention. For example, there may be variations in theshape and spacing of the various sections from that as indicated on thedrawing, or in locating and designing the port means. The apertures 22and 22' located on the perforate sections will of course be sized inrelation to the size of the catalyst particles which are to bemaintained within the apparatus. The physical shape for catalystparticles may be such that they are in the form of spheres, cylinders,or pellets, typically having a dimension of one sixteenth to one quarterinch, although particles of larger or smaller dimensions may be employedwhere desirable. Mixed sizes of catalysts may also be well utilized,especially as a means to provide for a low temperature catalyticoxidation process.

We claim as our invention:

1. In a catalytic converted for containing subdivided catalyst particlestherein for treating an engine exhaust gas, the combination comprising:

an outer housing which has an elongated tubular body section andopposing sealed end sections;

a first port means through said one end section, and a second port meansthrough the opposing end section;

a tapered, tubular-form, perforate section having an interior closed endand an open end, said tapered, tubular-form perforate section having itssaid open end connecting to said outer housing; and the remainingportion spaced within said outer housing to form a manifold sectiontherearound;

a central tubular-form perforate section having an open end and aninternal closed end spaced centrally within said tapered tubular-formperforate section to thereby provide an annular-form catalyst retainingsection for containment of said catalyst particles, the open end of saidcentral tubular-form perforate section extending to and connecting withone of said port means, said interior closed end of said tapered,tubular form section having a central support means therein for saidinternal closed end of said central tubular-form perforate sectioncomprising a centrally located opening therein sized to slideablyencompass and support the internal end of said centrally locatedtubular-form perforate section, a catalyst reservoir means adjacent saidclosed end of said tapered, perforate section, and a passageway meansfrom said reservoir means to said catalyst retaining section to permitflow from said reservoir means to said catalyst retaining sectionsresponsive to expansion of said central tubular-form section.

2. The converter of claim 1 further characterized in that thelongitudinal axis of said converter is substantially vertically disposedwith the catalyst reservoir section means located above said catalystretaining section to thereby permit the catalyst particles stored insaid reservoir section means to [flow downward as further induced bygravity through said passageway means into said catalyst retainingsection to fill voids therein.

3. The converter of claim 1 further characterized in that there isprovided spacing means spaced from one of said end sections, for supportof the closed interior end of said tapered tubular-form, perforate wallsection.

4. The converter of claim 1 further characterized in, that the open endof said tapered, tubular-form, perforate section is the wider endthereof.

5. The converter of claim 1 further characterized in that the outerelongated tubular body section and the tubular-form perforate sectionare cylindrically shaped and the tapered, tubular-form perforate sectionis conically shaped, and in that said sections are co-axially disposedabout the longitudinal axis of said tubular body section, wherebytemperature movement stresses are equalized in the radial direction.

6. The converter of claim 1 further characterized in that the elongatedtubular body section is symmetrically formed about the longitudinal axisthereof, the tapered tubular-form perforate section is conically shaped,and the tubular-form perforate section is cylindrically shaped, and inthat said sections are co-axially disposed about the longitudinal axisof said tubular body section, whereby temperature movement stresses areequalized in the radial direction.

7. The converter of claim 1 further characterized in that the endsections have flanged portions and the exterior dimensions thereofcoincide with the interior dimensions of said tubular body section tothereby be adapted to be disposed co-axially within said tubular bodysection.

References Cited UNITED STATES PATENTS 3,166,382 1/1965 Purse et a1.23288.3 F 3,413,096 11/1968 Britt 23-2883 F 3,485,319 12/1969 Ballufi181-35 JAMES H. TAYMAN, 111., Primary Examiner

